1. Field of Invention
Embodiments of the invention relate in general to the field of networking. More specifically, the embodiments of the invention relate to methods and systems for network management.
2. Description of the Background Art
Many of the network management functions performed by management applications require an initial stage of learning what is in the network and how it is configured, followed by an on-going requirement to monitor for changes in the configuration and/or in network state. One example of such an application is Inventory Management, which is responsible for collecting an inventory of all the managed devices in the network and building a local database of information. This information is used by other applications such as Inventory reporting, Configuration Management, Software Image Management, or any other. The information is stored in Management Information Bases (MIBs). Thus, MIBs contribute in the network management operations.
MIB is a conceptual database that stores network information. The MIB is a hierarchically structured collection of objects. Each object represents a particular type of information regarding the configuration or the state of a network device in a network. Exemplary network devices include, but are not limited to switches, routers, computers, and servers. A network management application, such as, ‘Inventory Management’, uses Simple Network Management Protocol (SNMP) to retrieve the information stored in one or more MIBs on the network devices. The network management applications make a local cache of the retrieved information for performing various management functions, such as, managing configurations of network devices, monitoring the network devices for faults and monitoring performance of the network devices.
The configuration and state of the network components in the network changes with time. For example, the active state of a network component may change to an inactive state in the event of failure of the network component. The information in the MIB is required to be monitored for these changes. Various methods and systems exist for monitoring changes in the MIB objects. One such method is user triggered, wherein the network information is updated when a network operator requests the management application for the same. In another method for monitoring MIB objects, the network operator programs the network management application to periodically update the network information using SNMP. However, this method results in redundancy of collection of network information.
The above two methods result in significant bandwidth usage of communication channels. In addition, these methods require significant usage of memory and processing unit of the network devices. This is because the information in the MIB is updated even in the event when the configuration and state of each network device in the network remains unchanged.
In another method for monitoring objects, a notification for a change in the information of the network device is sent to a network management application using SNMP. These notifications are in the form of syslogs or traps. This method requires syslogs or traps to be associated with the information required by each of the network management applications in the network. Further, the change notifications may not pertain to the information that the network management application requires. Thus, the entire information about the network device has to be updated by the network management application.
Selective polling is still another method for monitoring objects in the network. According to this method, indicator variables are defined in the MIB. An indicator variable is associated with a type of network information. A change in the indicator variables is determined by polling. The indicator variables are polled for detecting changes in the associated network information among the network devices. However, indicator variables are not available for every type of network information. In addition, the indicator variables are required to be polled periodically. Periodic polling still results in additional, albeit reduced usage of bandwidth of the communication channel.
Granular collection is yet another method for monitoring the MIB objects. In this method, the network information is divided logically into subsets. For example, flash information and inventory management can be subsets of network inventory information. The changes in the subsets are monitored by notification. The changed subsets are updated. The process of collection can be optimized by updating only those subsets that have undergone a change. However, the subsets further comprise a plurality of objects and changes in particular objects are not observed.